The development of blood-based or other diagnostic tests for the TSE diseases should be greatly facilitated by an integrated set of compatible resources: 1) a susceptible large animal (sheep) to provide blood or other substrates, 2) susceptible transgenic rodents that can be used as a sensitive bioassay, 3) standard reference samples of brain, blood, and plasma of sufficient volume to be used by the TSE community. We are breeding a flock of 50 genotyped sheep to select for the high scrapie susceptibility genotype VVRRQQ. All three lines of the mouse transgenics carrying sheep, human, and elk PrP have been now re-derived. We have observed the first transmission of the disease from our standard scrapie-infected sheep brain inoculum to the transgenic mice with sheep PrP and have completed an end-point dilution titration. We have pooled and aliquoted the infected sheep whole blood, and separately, plasma (100 liters total). The pooled whole blood and plasma have been inoculated into transgenic mice for limiting dilution titrations that will quantify their exact level of infectivity, thus increasing their value to researchers. A protocol for sharing or sale of these resources has been prepared and samples have already been distributed.